K2 Plus Filament Jamming Fix: I found in my particular case that the filament would jam up inside the PTFE connect on the backside of the printer, where the tubing goes from the buffer to the printer. You can see I completely removed that connector and ran one complete PTFE line from the buffer to the print head. I kept the locking connector on the inside which keeps the tubing from pushing in or out of the inside of the printer enclosure. This seems to have rectified a lot of my problems with the CFS, not sure if this has been addressed already but I hope it helps others.